import java.util.Scanner;

/**
 * User:langchen
 * Date:2022-07-27
 * Time:14:39
 */
public class judgement {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int num = sc.nextInt();
        int j = 2;
        while(j<num){
            if(num%j==0){
                System.out.println(num+"不是素数");
            }
            else{
                j++;
            }
        }
        if(j>=num){
            System.out.println(num+"是素数");
        }
    }
}
